Needle structure



vvides a continuation of the cannula bore.

Patented July 10, 1951 NEEDLE STRUCTURE Garwood W. Ferguson, Paterson,N. J., assigner to Becton Dickinson and Company, Rutherford, N. J., acorporation of New Jersey Application February 10, 1950, Serial No.143,399

(Cl. 12S-221) 4 Claims.

This invention relates to afunctionally improved hollow needle orcannula structure.

It is an object of the invention to furnish a structure of thisnaturegwhich may pierce layers of material or skin and tissue withoutsevering a plug from such materials.

Accordingly, in the case of a needle which is caused to puncture adiaphragm, stopper or other sealing portion of a pharmaceutical closure,material will not be cut from such closure.r Therefore, there will be nodanger of the bore of the cannula becoming clogged, nor will there beany danger of a plug dropping into the receptacle to which the seal isapplied. Where the invention is embodied in a hypodermic needle and thelatter pierces skin and underlying tissues no embolus will be cut.

An additional object of the invention is that of furnishing a device ofthis type which may readily be manufactured by quantity productionmethods and with minimum expense; the needle structure being equallyapplicable to cannulae which are merely intended to pierce closures orcannulae which are primarily intended for hypodermic injection purposes.

With these and other objects in mind, reference is had to the attachedsheet of drawings illustrating one practical embodiment of the inventionand in which:

Fig. 1 is a face view of a needle and showing the same mounted by a hubor coupling member such as would ordinarily be employed in connectionwith a needle. to puncture diaphragms of rubber or other materialsproviding pharmaceutical closures; 1

Fig. 2 is a fragmentary enlarged face view of the pointed needle end;

Fig. 3 is ya side view thereof;

Fig. 4 is an end view of the needle point;

Fig. 5 is a sectional side view of a thin material layer pierced by aneedle, also shown in section;

Fig. 6 is an end view of the parts as shown in Fig. 5.

Referring primarily to Fig. 1, the numeral 5 indicates a cannula orhollow needle which, as shown, may be mounted upon a hub including aforward portion 6 and a tubular rear portion This hub convenientlyincludes as part of its assembly a shield 8. The forward portion 6 ofthe hub is formed with a bore 9 which proneedle is pointed at its outerend as generally indicated at I0 to furnish a piercing end or part.

Referring in detail to the structure provided adjacent the point of theneedle it will be seen The as in Figs. 2, 3 and 4 that this may includea generally obliquely extending surface. This surface or zone preferablyembraces forward side beve'ls I I, to the rear of which the groundsurface I2 extends. Within the zone of surface I2 the end of the bore I3is defined. To the rear of this bore is the heel portion of the needle.The forward bevel surfaces II merge as at I4 and this line of merger iscontinued to furnish the piercing point at the extreme end of theneedle.

In accordance with the present teachings, the heel portion of the needlepoint is depressed as indicated at l5. Such depression extends to therear of the zone of the ground surface. Also, this depression interruptsthe rearvzone of the ground surface.

To provide a unit of this character, a cannula is cut to lengths in theusual manner. Also, in

the usual manner the end of the cannula is ground to furnish theobliquely extending surface as well as the side bevels Il whichinterrupt or form continuations of the forward end of that surface.Thereafter, the heel portion of the needle is subjected to pressureexerted through a press mounting a suitable tool. In this manner thedepression I5 is formed to dene this heel portion. Thereupon, thecannula and the point are complete. At any stage in the manufacture, asuitable hub portion may be associated with the cannula.

As a result'of the depression which is formed to provide the heelportion, no plug will be severed from a layer or layers pierced by aneedle embodying the present teachings. Rather, if a thin layer I6 ispunctured as shown in Figs. 5 and 6, the layer will have a ap portion I1extending laterally from it and usually in direct sliding contact withthe outer surface of the cannula 5. This ap portion will be attachedthrough a substantial part of its circumference to layer I6. Therefore,there will be no danger of the flap beingsevered and detaching from themain layer during the piercing operation.

Where a relatively thick diaphragm or other closure layer is puncturedby the needle, the point and adjacent edges of the latter will cut anarcuate slit as they initially pierce that layer. This slit may extendthrough substantially Continued projection of the needle will result inthis slit being stretched or spread by' the wedging action of the needlesurfaces. Accordingly, a plug of material will in no case be depositedwithin the interior of a laboratory ilaslcv or bottle with consequentobjectionable appearance to the contents of that receptacle and possiblecontamination of such contents. Neither will a plugcome into being whichwill tend -to or actually ride into. the lumen of the cannula.. Wherethe structure is embraced inhypodermic needles, no embolus will be cutand therefore the patient will experience no danger in this connection.

Thus, among others, the several objects ot the invention as speciiicallyaiore noted are achieved. Obviously numerous changes in construction andrearrangement of the parts may be resorted to without departing. fromthe spirit of the invention as deiinedby the claims.

1. A needle structure including a cannula I formed with a piercing pointat one end. bevel surfaces extending rearwardly from said point andpresenting a line of merger, a further surface extending obliquely fromsaid bevel surfaces rearwardly across the cannula, a. heel portion atthe rear end of said oblique surface and a depression formed in the heelportion.

2. A needle structure including a cannula formed with a piercing pointat one end, a surface extending obliquely `from said point rearwardlyacross the cannula, the outer end oi' the cannula bore terminating insuchsuriace. a heel portion contiguous with said surface and having itsforward boundary defined by the rear edge cannula bore terminating insuch surface, a heel portion contiguous with said surface and having'itsforward boundary deiined by the rear edge portion of the cannulabore and said heel portion being depressed throughout its entire area inthe direction of the needle axis and below the outer cannula surface.

4. A needle structure including `a. cannula formed with a piercing pointat one end. a surface extending obliquely from said point rearwardlyacross the cannula, the outer end of the cannula bore terminating insuch surface, a heel portion-contiguous with said surface andhavingGARWOOD W. FERGUSON.

REFERENCES CITED The following references are of record in the Ille ofthis patent:

UNITED STATES PATENTS Number Name Date 2,137,132 Cooley a- Nov. 15, 19382,409,979 Huber Oct. 22. 1946 FOREIGN PATENTS Number Country Date466,002 Great Britain May 20, 1937 453,877 France Apr. 16, 1913 739,717

France Jan. 16, 1933

